Combined capillary gas chromatography-negative ion chemical ionization mass spectrometry provid and quantitation of low-levels of prostaglandins, leukotrienes, platelet-activating factor (PAF), hydroxy-eicosanoids, keto-eicosanoids and diacylglycerides in complex biological fluids. Funds are requested for the purchase of a Finnigan MAT SSQ-700R single stage quadrupole GC/MS/DS with additional data system 8-Mb RAM expansion and two buck/boost transformers (acquisition cost - $264,700) to be shared by ten co-investigators. The instrumentation will be used to provide dedicated instrumentation for combined capillary gas chromatography-negative ion chemical ionization mass spectrometric techniques critical for determination of the role of lipid mediators in human asthma, allergy, pulmonary disease and pulmonary injury. The prostaglandins, leukotriene B4, hydroxy-eicosanoids, keto-eicosanoids and the diacylglycerides are directly converted to electron-capture derivatives with suitable vapor phase properties via facile reaction with multifluorinated reagents. The sulfidopeptido- leukotrienes (leukotrienes C4, D4 and E4) and PAF are chemically modified prior to synthesis of electron-capture derivatives. The sulfidopeptido group of leukotrienes C4, D4 and E4 is removed leaving an eicosanoid skeleton which is then converted to the pentafluorobenzyl ester. The phosphate ester of PAF is hydrolyzed prior to synthesis of the diglyceride pentafluorobenzoyl ester derivative. The exquisite sensitivity (detection limits < 100 fg/injection) of combined capillary gas chromatography-negative ion chemical ionization mass spectrometry has resulted in the adaptation of simplified and less labor-intensive purification procedures than previously required in mass spectrometric assays. In turn, more complete determinations of the profiles of lipid mediators in biological samples are obtainable. The proposed instrumentation should provide information for more rational approaches in the prevention, management and treatment of asthma, allergy, pulmonary disease and pulmonary injury.